1. Field of the Invention
The present invention pertains to the detection of leakage from an underground storage cavern which is used for the bulk storage of liquid hydrocarbons.
2. Description of the Related Art
A primary technique heretofore used for detecting leakage in storage caverns uses wireline equipment to lower sensors into the well bore for detecting the gas/liquid interface and typically for measuring other parameters such as temperature and pressure.
This equipment is used in conjunction with nitrogen gas injection to establish conditions for measuring leakage of gas or liquid from the cavern. Wireline equipment has the disadvantages of high cost, for both equipment and labor, and gas leakage through the wireline packoff (gasket) which is subject to friction deterioration due to the movement of the wire through the packoff.